Longitudinal guide for a motor vehicle seat

ABSTRACT

A longitudinal guide for vehicle seats, including two elongate rails, each including a lower rail, an upper rail supported on the lower rail and displaceable in a longitudinal direction, and two bearing areas for guiding means, the bearing areas lying diagonally opposite to and biased against each other, each upper rail and lower rail having an L-shaped region, if viewed in profile, formed by a base leg and an L-leg protruding from the base leg substantially perpendicularly, and two end regions adjoining the L-shaped region, each end region of the upper or lower rail together with the end region of the associated lower or upper rail forming an embracing area by mutually hooking, the end regions of the upper rail forming the bearing areas with opposite portions of the associated lower rail, and a plurality of balls being supported in a first bearing area on the end region.

The present application claims priority of the following German patentor utility model applications the whole content of which is herebyexpressly incorporated by reference for disclosure purposes: DE 10 2010021 852 “Longitudinal guide for a motor vehicle seat”, filed on 28 May2010; DE 10 2010 017 328 “Longitudinal guide for a motor vehicle seat,”filed on 10 Jun. 2010; DE 10 2010 017 329 “Longitudinal guide for amotor vehicle seat” filed on 10 Jun. 2010; DE 10 2010 017 330“Longitudinal guide for a motor vehicle seat,” filed on 10 Jun. 2010; DE10 2010 060 538 “Longitudinal guide for a motor vehicle seat” filed on12 Nov. 2010; DE 20 2010 000 957 “Longitudinal guide for a motor vehicleseat”, filed on 21 Apr. 2010.

FIELD OF THE INVENTION

The present invention relates to a longitudinal guide for a motorvehicle seat with two lower rails, which are directly or indirectlyfixed to the bottom of the interior on both sides of the motor vehicleseat.

BACKGROUND OF THE INVENTION

In the case of such a longitudinal guide on each lower rail a slidableupper rail is disposed such that both rails form profile a substantiallyrectangular cross-section in their functional position, wherein bearingareas of the upper rail are formed on the lower rail as an embracingportion, which are disposed at the two corner areas of the rail profilesessentially diagonally opposite to each other and which have associatedguiding means, wherein end portions of the lower rail and of the upperrail are respectively formed as essentially U-shaped profiles in thebearing areas, which are engaged with each other.

WO 2006/106044 A1 of the Applicant discloses such a longitudinal guide,wherein a first upper bearing area, which uses a plurality of balls asguiding means, and a second lower bearing area, which is diagonallyopposite to the first bearing area and uses as guiding means acombination of rollers for supporting on a base leg of the lower railand balls, are biased against each other in diagonal direction in orderto accomplish a high rigidity of the rail profile. The balls in thefirst bearing area are mounted between two circular arc-shaped profiles,wherein one of the circular arc-shaped profiles forms a corner area atthe upper end of a connecting leg of the lower rail, which is upwardlyinclined at an acute angle and projects outwards relative to the rail.

Despite advantageous characteristics of this rail profile, there isstill room for further improvement, particularly as in terms of theinstallation space available for this purpose, the total width and thewidth at the lower end of the rail profile as well as in terms ofrigidity and the material or total weight required to implement it.Important in this context are particularly mechanical characteristics,especially the rigidity and torsional rigidity of the rail profile inthe event of a crash, be it a frontal or rear crash or a side crash.

DE 197 17 667 A1 discloses a further longitudinal guide for motorvehicle seats, wherein the end portions of the upper rail, which end inthe bearing areas that are diagonally opposite to each other, are formedwith multiple curved section so that in each embracing portionrespective two channels for balls are provided, if viewed in a crosssectional view, which act as guiding means. Precise formation of suchend portions can be accomplished only in a relatively complicatedmanner, so that the tolerances are relatively high. The play of thelongitudinal guide is further enlarged due to the higher wear, whichresults from the point contact of the ball-bearing guides.

JP 2004 203264 A discloses a further longitudinal guide for a motorvehicle seat, wherein a second bearing area in the sense of the presentapplication is provided but not at the same time a ball guide and aroller guide, but instead two ball guides. There exists no supportingleg, which is associated to the upper ball bearing and which includes anacute angle with another supporting leg. Rather, the ball is received inan arcuately shaped longitudinal bead.

EP 1 336 765 A discloses a longitudinal guide with double pairs of ballguides in each bearing area.

Further prior art is disclosed in the documents EP 1 621 390 A, DE 102004 061140 A, FR 2 872 102 A and US 2005/285008 A.

SUMMARY OF THE INVENTION

It is an object of the present invention to enhance a longitudinal guideof the afore-mentioned kind to the effect that an enhanced mechanicalrigidity especially in the event of a crash can be accomplished with asimple mechanical design and with minimum weight and materialconsumption. According to a further aspect of the present invention, thelongitudinal guide shall absorb loads more effectively, especially inthe event of a crash.

According to the present invention these objects are achieved by alongitudinal guide with the features according to claim 1. Furtheradvantageous embodiments are the subject-matter of the dependent claims.

Thus the present invention is based on a longitudinal guide for vehicleseats, in particular for motor vehicle seats, comprising two elongaterails, each having a lower rail and an upper rail supported on the lowerrail so as to be longitudinally movable, and two bearing areas forguiding means disposed diagonally opposite to each other and biasedagainst each other, each upper and lower rail having an L-shaped region,if viewed in profile, which is formed by a base leg and an L-legprojecting essentially perpendicularly therefrom, and two end portionsconnected to the L-shaped region, each end portion of the upper or lowerrail forming an embracing portion with the end of the associated loweror upper rail under mutual interlocking, and the end portions of theupper rail together with opposite portions of the associated lower railforming the bearing areas, and wherein a plurality of balls aresupported in a first bearing area at the end portion, which is formed asa circular arc-shaped profile.

According to the invention, the first bearing area is formed by a cornerarea of the lower rail and the end portion of the upper rail, which isformed as a circular arc-shaped profile, in order to support theplurality of balls, wherein a first connecting leg projects from theL-leg of the L-shaped region of the lower rail horizontally or slightlyinclined below a bending area of the upper rail and projects outwardsand wherein the corner area is formed at a second connecting leg that isconnected with the first connecting leg.

According to a first embodiment the aforesaid first, outwardlyprojecting connecting leg can extend upwards relative to a horizontalline or to the base leg of the lower rail under a relatively small acuteangle, in particular in the range between 10° to 30°, preferably 15° to20°.

According to a further preferred embodiment, the first connecting legmay alternatively extend substantially in a horizontal direction andoutwardly from the L-leg of the L-shaped region of the lower rail. Insuch an embodiment a particularly effective support of an opposite legof the profile can be accomplished in particular under the action ofsubstantially downwardly directed forces, such as these may occur forexample in the event of a crash, in that the opposite leg of the profileis pressed downward and finally gets into contact with the firstconnecting leg which extends in horizontal direction and outwardly. Afurther sliding of the opposite leg directed inwards into the rail isthereby effectively prevented by the substantially horizontal directionof the first connecting leg.

According to a further preferred embodiment the first connecting leg mayalternatively extend at a relatively small acute angle relative to ahorizontal line or to the base leg of the lower rail downward, inparticular by an angle in the range between 10° to 30°, preferably 15°to 20°. In such an embodiment a particularly effective support of anopposite leg of the profile can be accomplished in particular under theaction of substantially downwardly directed forces, such as these mayoccur for example in the event of a crash, in that the opposite leg ofthe profile is pressed downward and finally gets into contact with thefirst connecting leg extending obliquely downward and outwardly. Afurther sliding of the opposite leg directed inwardly into the rail isthereby effectively prevented, since the opposite leg of the profile canonly continue sliding outwardly from the rail in the case of a contactto the first connecting leg extending obliquely downward, but cannotslide inwardly into the rail while being in contact.

According to a further embodiment the contact points of the balls at theend portion in the form of a circular arc-shaped profile, as viewed froman interior of the rails, are particularly preferably on a side oppositeof a virtual center line through the L-leg of the L-shaped region of thelower rail. Here, the contact points of the balls preferably can be veryclose to the virtual center line, so that the absorption of forcesacting in the vertical direction directly into the underneath L-leg ofthe lower rail can be accomplished, which is more stable, i.e. has ahigher material thickness, which enables very short levers forabsorption of forces and thus further increases the stiffness. Incomparison to the prior art, where the first bearing area is alwayslocated completely outside of the rectangular inner region of thelongitudinal guide, the first bearing area, which is located near thetop of the longitudinal guide, partially overlaps with the inner space,so that the width of the longitudinal guide at the lower end thereof (orthe projection of the first bearing area on the base leg of the lowerrail) overall can be significantly shortened. This provides significantadvantages and additional degrees of freedom in the design of theinterior of motor vehicles. In particular, the necessary space for thelongitudinal guide in the transverse direction of the vehicle can bereduced, in particular directly on the floor of the vehicle interior.

The corner area formed by the two connecting legs in conjunction withthe opposite circular arc-shaped bearing profile and the balls supportedin between in the bearing area results in an advantageously highrigidity in the first bearing area. Particularly an escape of the ballsin the vertical or horizontal direction is effectively prevented even athigh loads, such as these can occur in the event of a crash. Because theballs are partially embraced, as defined by the circular arc-shapedbearing profile, and due to the corner area, the inner curvature ofwhich matches with the radius of curvature of the balls to be supportedand is preferably slightly smaller than this radius of curvature, canthe balls be supported very precisely in the first bearing area, whichis advantageous for the overall tolerances of the longitudinal guide andtheir adjustment characteristics and which enables a relatively lowsurface pressure at the contact points of the balls with associatedbearing areas.

According to a further embodiment the two connecting legs enclose witheach other an angle in the range from 100° to 120°, more preferably anangle in the range from 112.5° to 107.5°, and more preferably an angleof about 110°, to accomplish a high rigidity and a precise support inthe first bearing area.

According to a further embodiment, the aforementioned corner area isconnected to a first connecting leg, which projects outwards from theL-leg of the L-shaped region of the lower rail and to a subsequentsecond connecting leg, which extends obliquely upwardly and outwardlyfrom the rail profile. The first connecting leg conveniently has arelatively short length, so that the balls to be supported in the firstbearing area are not located too far outside of the L-shaped region ofthe lower rail. Here, the second inclined connecting leg convenientlyprojects under an acute angle, particularly an angle in the rangebetween 50° and 70°, more preferably of about 60°, obliquely upwardlyand in the direction of the corner area. For this purpose, the materialof the lower rail is suitably bent. This configuration allows anadvantageously high stiffness while exhibiting a convenient resilientbehavior under normal loads.

Very particularly preferably in accordance with a further embodiment,the distance of the contact points to the virtual center line is lessthan a material thickness of the upper rail, and in particular of theorder of half the material thickness of the upper rail. Howeveraccording to a further embodiment, the distance of the contact points tothe virtual center line can in principle correspond to the materialthickness of the upper rail or be of the same order.

According to a further embodiment, the contact points of the balls inthe first bearing area are also on one or a little outside of a virtualextension line of the outer side of the L-leg of the L-shaped region ofthe lower rail, as seen from the inside of the rails. Here, the distancebetween the contact points to the virtual extension line is preferablyin any case considerably smaller than the material thickness of theupper or lower rail. It is an advantage that at a certain strain of thelongitudinal guide due to a vertical load, especially by a normal-weightperson sitting on the vehicle seat, the contact points can just come tolie on the virtual extension line (or in its immediate vicinity) and soforces can be absorbed and transferred even more effectively.

According to a further embodiment, the dimensions of all gaps in theembracing portions of the bearing areas in the vertical direction (z),i.e. in the direction perpendicular to the base leg of the L-shapedregion of the lower rail, are all the same and smaller than a materialthickness of the upper rail. By this measure, even in the event of aside crash with excessive forces acting on the longitudinal guide in thetransverse direction of the vehicle and resulting plastic deformation ofthe rail profiles a simultaneous contact of portions of the railprofiles, which are directly opposite to each other in the transversedirection of the vehicle, is made possible, which results in anadditional stiffening of the rail profiles in a transverse direction ofthe vehicle and thus results in more favorable crash characteristics.

According to a further embodiment, the dimensions of all gaps in theembracing portions of the bearing areas parallel to the base leg of theL-shaped region of the lower rail are all the same and smaller than amaterial thickness of the upper rail. Thus, in the event of a side crashwith an excessive force acting on the longitudinal guide in the vehicletransverse direction and thereby caused plastic deformation of the railprofiles a simultaneous contact of portions of the said profile, whichare opposite to each other in the transverse direction of the vehicle ismade possible, which results in an additional stiffening of the railprofile in the transverse direction, thus leading to more favorablecharacteristics in the event of a side crash.

According to a further embodiment an upper surface of the base leg ofthe L-shaped region of the upper rail protrudes from an upper reversalarea of the lower rail in the embracing region of the first bearing areaby a predetermined distance, this distance being smaller in an unloadedstate of the longitudinal guide than two times the material thickness ofthe upper rail. This allows a certain amount of “breathing” of the railprofile upon a vertical load, in particular in the operating positionwhen a relatively heavy weight person takes place on the vehicle seat.In this loaded normal state the rail profile can sag or collapse to theextent that dimensions of the gaps in the vertical direction are reducedaccordingly, for example up to the order of about 0.5 mm for most obesepeople, having a body weight of, for example, 120 kg to 150 kg.

According to a further embodiment, a predetermined bending position isprovided in the transition area between a connecting leg, which isopposite to the L-leg of the upper rail, and the adjoining end portion.While the connecting leg and the predetermined bending position arefollowed by a first bearing area, the L-leg of the upper rail isfollowed by a second bearing area, which is diagonally opposite to thefirst bearing area. The predetermined bending position thus allows aconsiderably higher load of the longitudinal guide in the verticaldirection (z) as compared with the prior art without modifications ofthe ball guide, but at the same time enables a higher stiffness inextreme situations, in particular in the event of a crash, when highaccelerating and deforming forces act on the longitudinal guide. In suchextreme situations the predetermined bending position leads to acontrolled deformation or bending of the longitudinal guide andtransfers it into a state in which a high degree of stiffness andtorsional strength is accomplished. At the same time the predeterminedbending position results virtually in a load reversal so that asubstantially vertical load basically becomes a load in the transversedirection of the longitudinal guide, which can be absorbed efficientlydue to the higher material thickness and stiffness of the rail profileof the lower rail.

The predetermined bending position is in particular configured such thatvertical downward forces result in a bending of the upper rail both invertical direction (z) and in the vehicle transverse direction (y). Incooperation with the diagonally opposite second bearing area, whichdecomposes downward forces in a corresponding manner into two forcecomponents, namely, a force component in the vertical direction (z) anda force component in the vehicle transverse direction (y), however, inthe opposite direction, thus a higher stiffness of the longitudinalguide can be accomplished. Thus, in particular the overall height of thelongitudinal guide can be increased, and for achieving a predeterminedstiffness a smaller width of the lower rail or a smaller overall widthis necessary.

According to a further embodiment, such a predetermined bending positionis formed in an advantageously simple manner such that it is less stiffthan an adjacent bent or curved region of the upper rail, which can beaccomplished in particular by the fact that the one or more adjacentbent or curved regions of the upper rail is provided with an embossingor embossment formed by cold working.

Such embossings or embossments can be implemented in particular by meansof projections, bevels or the like using bending tools, wherein it ispreferred that the embossings or embossments are formed uniformlycurved.

The adjacent bent or curved regions, which are each provided with theembossment or embossing, are according to a further embodiment a cornerarea at the upper end of the L-shaped region of the upper rail and atransition area between an inclined connecting leg, which follows theconnecting leg opposite to the L-leg of the upper rail, and an endportion of the upper rail, which is formed as a circular arc-shapedprofile. The inclined connecting leg can thus allow for a compensatingmovement with components in both the vertical direction and in thevehicle transverse direction upon a normal loading of the longitudinalguide, and thus a certain degree of “breathing” of the rails in thevertical direction.

According to a first embodiment the inclined connecting leg can extendobliquely downwards and outwards from the rail or according to a secondembodiment obliquely upwardly and outwardly from the rail. Herein atransition area between the connecting leg, which extends obliquelydownward (or upward) and outwardly and the end portion of the upper rail(2), which is formed as a circular arc-shaped profile, is preferablyformed as a bending position, which is located substantially on avirtual center line through the L-leg of the L-shaped region of thelower rail, which extends substantially perpendicularly from the baseleg. More preferably, the bending position is located exactly on thisvirtual center line. Preferably, the distance of this bending positionto this virtual center line is in any case much smaller than thematerial thickness of the upper rail and lower rail. By means of thisconfiguration, a transfer of forces acting in vertical direction to theL-leg of the lower rail, which located directly below and is aligned andwhich is more stable, i.e. formed with increased material thickness, canbe accomplished, which enables very short levers for the transfer offorces and thus a further increase in stiffness. In comparison to theprior art, according to which the first bearing area is alwayscompletely outside of the rectangular interior of the longitudinalguide, the first bearing area, which is located near the upper side ofthe longitudinal guide, partially overlaps with the inner space, so thatthe lower width of the longitudinal guide overall can be significantlysmaller. This provides significant advantages and additional degrees offreedom in the design of the interior of motor vehicles. In particular,the necessary space for the longitudinal guide in the transversedirection can be reduced, in particular directly on the floor of thevehicle interior.

According to a further embodiment, the upper rail is bent by about 180°in region of the afore-mentioned bending position, i.e. is substantiallyformed as a reverse area wherein the profile of the upper railsubstantially reverses its direction of extension. By means of thisconfiguration a certain degree of elasticity is provided in the regionof the bending position or of the reverse area, so that the rail can“breathe” sufficiently at normal load changes, but may still have asufficient rigidity at extreme loads, particularly in the event of acrash.

In the aforementioned first embodiment wherein the inclined connectingleg extends obliquely downward and outwardly from the rail, a certainvertical load, resulting in particular from the weight of a normalweight person sitting on the vehicle seat, as described above, can beconverted into a load in the transverse direction, resulting in afurther increase of the diagonal biasing of the two bearing areas, andtherefore contributes to a further increase in the stiffness of thelongitudinal guide.

The aforesaid second embodiment, wherein the inclined connecting legextends obliquely upwardly and outwardly from the rail is furtheroptimized for crashes, since this connecting leg directly gets intocontact with an opposite portion of the lower rail in the event of acrash.

According to a further embodiment, the bending position between theinclined connecting leg and the end portion of the upper rail formed asa circular arc-shaped profile is located at a distance to theaforementioned first inclined connecting leg of the lower rail, whichextends obliquely upwards and outwardly from the rail and which directlyfollows the L-leg of the L-shaped region of lower rail. According to theinvention a particular advantageous support of the opposite bendingposition and hence of the entire first bearing area can be accomplishedin the event of a crash. Namely, the bending position or the reversalarea can be supported on the opposite inclined first connecting leg,without slipping, however, into the L-shaped region or into the interiorof the lower rail. This is prevented in particular because the oppositeinclined first connecting leg extends at a relatively small acute anglerelative to a horizontal line.

According to a particularly preferred embodiment, in the second,diagonally opposite lower bearing area two groups of rollers aremounted, namely a plurality of first rollers, which are supported withlateral play between the base leg of the L-shaped region of the lowerrail and a supporting leg of the upper rail, which is opposite theretoand extends in parallel therewith, and a plurality of second rollers,which are supported between the end portion of the upper rail, whichextends obliquely upwards at an acute angle, and an opposite inclinedsupporting leg, which is opposite and extends in parallel and is locatedbetween a supporting leg, which adjoins the base leg and extendsobliquely upwards, and an adjoining horizontal base leg of the embracingportion in the end portion of the lower rail. By means of the two groupsof rollers overall an advantageously low surface pressure in the secondbearing area can be accomplished, so that the rail profile is “ready foruse” during use as compared to systems, in which a group of balls isprovided in the second bearing area. Another advantage is that therollers of the two groups of rollers always run at the same speeds. Insystems where a group of balls is provided in the second bearing area,this is not always the case, since there the speed depends from theexact (load-dependent) point of contact. At identical speeds, however,there are no problems using a common bearing cage for both groups ofrollers in the second bearing area. Another advantage is that by meansof the inclined lines of the support of the upper group of rollers inthe second bearing area, a weight force can be transferred from above tothe bottom right corner area, without causing changes in the runningbehavior of the rails. In systems, in which a group of balls is providedin the second bearing area, there would be significant kinematic changesinstead.

The rollers of the upper group of rollers in the second bearing area canin this case have a smaller diameter than the rollers of the lower groupof rollers, for example a diameter of less than 3.0 mm, which enables afurther extra space in the vertical direction in comparison to systems,in which a group of balls is provided in the second bearing area.Finally, a further extra space results from the fact that the uppergroup of rollers is supported on inclined supporting legs, so that theouter profile of the group of rails in this area has an inclined cornerand thus a corner, which is further offset inwards.

OVERVIEW ON DRAWINGS

The invention will now be described by way of example and with referenceto the accompanying drawings, from which further features, advantagesand problems to be solved will become apparent. In the drawings:

FIG. 1 shows a sectional view of a longitudinal guide according a firstembodiment of the present invention;

FIG. 2 shows the longitudinal guide according to FIG. 1, whereindistances and lengths subsequently to be discussed are designated;

FIG. 3 shows the geometrical longitudinal guide according to FIG. 1,wherein other important characteristics are shown;

FIG. 4 is a sectional view of a second embodiment of the longitudinalguide according to the present invention;

FIG. 5 a is a longitudinal guide according to a third embodiment of thepresent invention;

FIG. 5 b shows a longitudinal guide according to a fourth embodiment ofthe present invention;

FIG. 6 is a sectional view according to the first embodiment of thelongitudinal guide of the present invention with a locking device of afirst exemplary embodiment of a longitudinal guide for motor vehicleseats;

FIG. 7 shows a sectional view of the longitudinal guide according to thefirst embodiment with another exemplary locking device;

FIG. 8 is a sectional view of the longitudinal guide according to thefirst embodiment having another exemplary locking device and an easyentry mechanism;

FIG. 9 a sectional view of a longitudinal guide according to the firstembodiment, with a further exemplary locking mechanism and with an easyentry mechanism;

FIG. 10 a sectional view of a longitudinal guide according to the firstembodiment with a modified guide web of the locking device according toFIG. 6, in which also the base leg of the lower rail is modified;

FIG. 11 a sectional view of a longitudinal guide according to a fifthembodiment of the present invention;

FIG. 12 a partial perspective view from above of a lower rail withlocking teeth for a locking device (not shown) according to a furtherembodiment;

FIG. 13 a magnified partial view of the lower rail according to FIG. 12;

FIG. 14 a partial perspective view from above of a lower rail withlocking teeth for a locking device (not shown) according to anotherembodiment;

FIG. 15 a partial perspective view from above of a lower rail withlocking teeth for a locking device (not shown) according to a furtherembodiment;

FIG. 16 a partial perspective view from above of a lower rail withlocking teeth for a locking device (not shown) according to a furtherembodiment;

FIG. 17 a partial perspective view from above of a lower rail withlocking teeth for a locking device (not shown) according to a furtherembodiment;

FIG. 18 a partial perspective view from above of a lower rail withlocking teeth for a locking device (not shown) according to a furtherembodiment;

FIG. 19 a sectional view of a longitudinal guide according to a furtherembodiment of the present invention; and

FIG. 20 a cross sectional view of another exemplary modification of thefurther embodiment according to FIG. 19, with an exemplary lockingdevice and easy-entry mechanism as described with reference to FIG. 8.

In the drawings, identical reference numerals designate identical orsubstantially equivalent elements or groups of elements.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A vehicle seat not shown in the drawings is directly or indirectly fixedto the bottom of the interior of the motor vehicle, which is likewisenot shown in detail, via two rail guides, which are disposed on bothsides and extend in the longitudinal direction of the vehicle(x-direction). Here, the upper rail 2 is supported longitudinallydisplaceable on the bottom rail 4 and is locked by means of a lockingdevice, as described below in more detail, at an appropriate position.In its operating position, that is, in the assembled state, the upperrail 2 and the lower rail 4 together form a substantially rectangularcross-sectional profile. Therein, the upper rail 2 and the lower rail 4are each formed as an L-profile, as explained in more detail below, sothat the bearing areas 3, 5 of the upper rail 2 on the lower rail 4 arediagonally opposite to one another. In order to prevent the upper rail 2from lifting off from the lower rail 4, embracing portions are formed inthe bearing areas 3, 5, which are discussed in detail below.Furthermore, the two bearing areas 3, 5 are biased against each other asa result of the geometry and material characteristics of the railprofiles. In all embodiments the rail profiles are formed without aprofile branch, so they can be manufactured by forming a steel sheetblank, for example, by bending, embossing, rolling or similar. Althoughsheet steel is preferred as the material for the rail profiles 2, 4,generally also light metals can be used, in particular aluminum. Therail profiles can also be implemented in a mixed structure, for example,the lower rail 4 as an aluminum profile and the upper rail 2 as a steelsheet profile. To achieve a high stiffness and crash resistance, it ispreferred, however, according to the invention when both rail profiles2, 4 are made of sheet steel.

Each rail 2, 4, has a respective L-shaped region, if viewed in profile,which is approximately in the middle of their profile blank and which isrespectively formed by a base leg and an associated L-leg, namely, inthe case of the upper rail 2 by the base leg 20 and the L-leg 21extending basically perpendicular and in the case of the lower rail 4 bythe base leg 40 and the L-leg 41 extending basically perpendicular. Mostpreferred according to the invention is a right angle between the baseleg and the associated L-leg. But conceivable are in principle alsosmall angular deviations from this geometry. Each leg of a rail is ineach case substantially parallel, preferably exactly parallel to anL-leg of the other rail, and also the two base legs 20, 40 extendparallel to each other. Essentially the base legs 20, 40 and theassociated L-legs 21, 41, define a free interior space I within the railprofiles, which is rectangular. Hereinafter, this free interior space isalso named a longitudinal channel and can generally be used forinstallation of components. Preferably, this inner space I is completelyfree of any guiding means. According to the invention, this longitudinalchannel can be adjusted according to the specific application, for whichpurpose the lengths of the base legs, L-legs and other projecting legsof the upper and lower rail 2, 4, can be adjusted suitably. Thus, evenrelatively large free cross-sections can be implemented, for example,relatively high and/or relatively wide longitudinal channels. Asexplained in more detail below, the rail profile of the presentinvention is generally tuned and optimized for a high mechanicalrigidity and torsional strength during a crash and at the same time forexceptionally low total width in transverse direction of the vehicle(y-direction) and ease of use. Other parameters for this complexoptimization process are in particular the material strengths of theupper and lower rail 2, 4, bends and embossings of the rail profiles.Similarly, also the angular relationships can be adapted in a suitablemanner.

If viewed in profile, each of the base legs 20, 40 and each of theL-legs 21, 41 is followed by an end portion which is formed as anembracing portion and in which suitable guiding means, are mounted,namely balls 7 in the first bearing area 3 and rollers 8, 9 in thediagonally opposite second bearing area 5, as outlined below, and in thecase of an electrically operated longitudinal guide also slides or slideprofiles.

More specifically, the L-leg 21 of the upper rail 2 is followed by asupporting leg 22, which projects under a right angle from it andextends in parallel with the base leg 40, and by an inclined supportingleg 23 (free end of the profile of the upper rail 2), which is bent atan acute angle and is formed flat or planar, that is without arcuaterecesses. Furthermore, the base leg 40 of the lower rail 4 in theright-hand part of FIG. 1 is extended to the bending region between thesupporting leg 22 and the inclined supporting leg 23. The base leg 40 isfollowed by a connecting leg 49, which is bent under a right angle andextends vertically, that is in z-direction (vertical direction), whichmerges into an inclined supporting leg 50, which is opposite to theinclined supporting leg 23 of the upper rail and extends parallel to thelatter. In the region between the two inclined supporting legs 23, 50,the rollers 8 are mounted with a predetermined lateral clearance. Theinclined supporting leg 50 is followed by a base leg 40 extendingparallel to the base leg 51 in the right embracing portion. The frontfree end of this base leg 51 is bent at a preferably right angle, sothat the front free end 52 extends into the gap between the L-leg 21 ofthe upper rail 2 and the inclined supporting leg 23. Thus, in the secondbearing area 5 of the rail profile two embracing portions are formed,which are engaged with each other substantially like hooks.

In the left-hand part of FIG. 1 the base leg 20 of the upper rail 2 isfollowed by a connecting leg 24, which projects under a right angle andextends up to the front free end 48 of the lower rail 4 and is suitablybent in this area 29 to merge into an inclined connecting leg 25, whichextends at an acute angle, in the embodiment of about 45°, from theconnecting leg 24 downwardly and outwards from the rail. At the lowerend of the inclined connecting leg 25, this leg is bent upwards in theregion 26 and merges into a free end 28 of the upper rail 2, which isformed as a circular arc-shaped profile. For this purpose, the bendingportion 26 at first merges into a short transition leg essentiallyextending in the z-direction, which is followed by circular arc-shapedarea 28 having a predetermined radius of curvature and matching to theballs 7 to be supported. The front free end 28 of the profile of theupper rail 2 extends in this area at an acute angle, in the embodimentof about 55°, obliquely upward and outwards from the rail. Furthermore,the L-leg 41 of the lower rail 4 is followed by an inclined connectingleg 42, which is bent at an acute angle, in this embodiment of about 20°and extends obliquely upward and outwards from the rail, which isfollowed by a second angled connecting leg 43, which extends at an acuteangle of for example about 25° relative to a vertical direction. Thisinclined connecting leg 43 is followed by an upper connecting leg 45,including an obtuse angle of about 110°. Between the second, inclinedconnecting leg 43 and the upper connecting leg 45, a corner area isformed, the inner curvature of which matches with the radius ofcurvature of the balls 7 mounted in this area and is in particularslightly smaller than this radius of curvature. In cooperation with theembracing portion 27 of the free end 28 of the upper rail 2 the cornerarea 44 bears the balls 7 reliably and precisely.

According to FIG. 1, the upper end of the second inclined connecting leg43 is at approximately the same level as the front free end 28 of theupper rail 2. The upper reversing area 47 of the lower rail 4 isfollowed by a free end 48 of the rail profile of the lower rail 4, whichprotrudes into the gap between the connecting leg 24 and the free end 28of the rail profile of the upper rail 2.

The transition area between the L-leg 41 and the first connecting leg 42is preferably formed by a longitudinal bead. As can be concluded easilyfrom FIG. 1, the location of the balls 7 in the first bearing area 3 inthe vehicle transverse direction (y-direction) is precisely defined bythe corner area 44 and the associated circular arc-shaped bearingportion 27. Overall, the balls 7 are guided precisely.

As already mentioned, the rollers 8 and 9, respectively can be mountedin the diagonally opposite second bearing area 5 with a certain lateralplay such that the balls 8 can make compensating movements in thetransverse direction of the motor vehicle (y-direction) in the case of aload and in the longitudinal direction of the motor vehicle(x-direction) in the case of an adjustment. Furthermore, rollers aremounted between the base leg 40 and the parallel and opposite supportinglegs 22 in the lower region of the second bearing area 5, which, owingto the line-shaped bearing of the rollers 9, do not work into thematerial of the rail profiles. The same also applies for the rollers 8.A bearing cage, which is not shown in FIG. 1 and which can be configurede.g. as described in the German utility model DE 20 2007 015 163 U1 ofthe applicant, which expressively shall be part of the presentdisclosure, connects the groups of rollers 8, 9 in the second bearingarea 5 in order to avoid a movement of the rollers 9 in the transversedirection of the vehicle (y-direction). These roller cages arepreferably formed integrally and from a plastic material. While in thecase of a mechanically actuatable longitudinal adjustment device onlyrollers are used as guide means, as described above, in the case of anelectrically actuated longitudinal adjustment device instead of theupper rollers 8 in principle also sliders or sliding profiles can beused in the second bearing area 5.

In this embodiment, the embracing portions are provided in the secondbearing area 5 outside the rectangular area I delimited by theL-profiles, whereas the embracing portions in the first bearing area 3partially protrude into this space, by which measure the overall widthof the rail profile in the transverse direction can be significantlyreduced according to the invention, resulting in a significant advantageof the rail profile according to the present invention. To allownevertheless a sufficient rigidity and torsional strength, particularlyin the event of a crash, the rail profile according to the presentinvention overall is relatively high, which further enhances a diagonalbiasing of the two bearing areas 3, 5 and provides additional benefitsin the use of the interior space I, especially opens new possibilitiesto lock or arrest a longitudinal adjustment device, as described in moredetail below with reference to FIGS. 6 to 10.

As shown in FIG. 3, the contact points 19 of the balls 7 at the circulararc-shaped bearing area 27 of the upper rail 2 is slightly outside of avirtual center line 18 of the L-leg 41, if viewed from the interior ofthe rail profile. By “slightly” in this context especially a distanceless than or equal to the thickness of the upper rail 2 is to beunderstood, more preferably less than half the thickness of the upperrail 2. In this way, the contact points 19 in the case of a certainelongation of the longitudinal guide by a vertical load, in particularby a person of normal weight sitting on the vehicle seat (not shown),can come to rest exactly on the virtual center line 18 of the L-arm 41,because the forces then can be transferred directly and linearly to thedirectly underlying L-leg 41 of the lower rail 4. According to a furtherembodiment the distance of the contact points 19 to the virtual centerline 18 also can be negligible, so that the contact points 19 lie on thevirtual center line 18. In this manner, the power flow in the bearingareas can be optimized under mutual entanglement of embracing portions,particularly in the event of a crash, because the forces resulting fromthe interlocking in the first bearing area 3 can be transferred directlyand linearly in the directly underlying L-leg 41 of the lower rail 4.Specifically, the symmetry of the embracing portions 19 and the locationof the contact points 19 can be configured such that the forces can betransferred exactly vertically (in z-direction) directly into theunderlying L-leg 41 upon interlocking of the embracing portions. Thisallows an optimized power flow, particularly in the event of a crash.According to the invention therefore the material thickness of the upperrail 2 can be selected to be much smaller than the material thickness ofthe lower rail 4. In other words, at the same weight per unit length ofthe guide rails according to the invention a significantly higherrigidity and torsional strength can be accomplished, particularly in theevent of a crash.

As can be concluded directly from FIG. 1, because of the skew of theinclined supporting leg 23 in the second bearing area 5 an interlockingcan be accomplished, which increases with an increasing load, whichespecially holds for the critical even of a crash. With increasing loadin the vertical direction (z), the rollers 8 are pushed more and moreinto the associated bearing area 5. Since the lever length of theslanted supporting leg 23 is relatively short and, as will be describedbelow, further measures for stiffening are taken in the transition areabetween the base leg 22 and supporting leg 23 (embossment of the railprofile), the relatively short inclined supporting leg 23 is bent to arelatively minor extent in the event of a crash as compared to otherlegs of the profile and thus serves as a precise reference surface forthe rollers 8 to be supported. Thereby the rollers 9 in the secondbearing area 5 perform compensating movements in transverse direction ofthe motor vehicle in the event of a crash or when a load is applied sothat the rail profile tries to perform compensating movements in they-direction upon vertical loads, in particular in the case of a crash,which are, however, significantly counteracted due to the significantlyhigher material thickness of the lower rail 4 according to the presentinvention, whereby overall a high stiffness and torsional strength isaccomplished.

The inclined connecting leg 25 acts as a resilient arm, which enhances adiagonal biasing of the two bearing areas 3, 5 against each other. Inorder to precisely adjust the biasing force and displacement force, inthe rail profile according to the present invention in particular theradius of the balls 7 can be suitably configured, which has a directinfluence on the diagonal bias as a result of the geometry.

Further important in the rail profile according to the present inventionis the cooperation of the embossings, which stiffen the material, and ofa predetermined bending position at the inclined connecting leg 25. Asshown in FIG. 1, embossings 11, 12, which are formed by cold deformation(cold working) and have a smaller radius of curvature, are formed at thetwo ends of the base leg 20 of the upper rail 2. Such areas of higherdislocation density in the microstructure of the metal can beaccomplished by means of suitable bending devices, which may be providedfor example with longitudinal projections. Because of the embossings alocal increase in the dislocation density is caused and thus a localhardening of the metal, which allows a higher stiffness. Overall, thetotal thickness of the material of the upper rail 2 may be reduced.According to FIG. 1 corresponding embossings or embossments are alsoprovided in the areas 13 and 14 which serve to further stiffen thesecond bearing area 5, in particular the inclined supporting leg 23.Optionally also in the area 15 a corresponding embossment may beprovided to stiffen the embracing portions of the lower rail 4. Furtherimportant in this context is the use of a corresponding embossment 10 inthe transition area between the inclined connecting leg 25 and thebearing portion 27 of the balls 7 in the first bearing area 3, that ison the inside of the bent portion 26. Overall, all the bending positionsin the profile of the upper rail 2 are provided with embossings orembossments, with the exception of the circular arc-shaped bearing area27 of the balls 7 as well as a further angled portion, which is to serveas a predetermined bending position and is denoted in the figures by thereference numeral 29. In comparison to the adjacent curved or bentportions of the upper rail 2 the region 29 is formed to be less rigid,in particular to have a smaller torsional rigidity. In the event of avertical load being applied to the rail profile, in particular in theevent of a crash, this predetermined bending position 29 buckles atfirst, so that the profile of the upper rail 2 is bent in particular inthe region 29, i.e. the inclined connecting leg 25 is pivoted about thepredetermined bending position 29 like a lever. This reinforces thediagonal bias of the two bearing areas 3, 5, but also ensures that thegaps are maintained in the embracing portions (as see furtherembodiments further below) if a load is applied, especially in the eventof a crash.

According to FIG. 1 the first connecting leg 42 of the profile of thelower rail 4 is spaced apart from the bending portion 26 of the upperrail 2 (gap e, see FIG. 2). In the event of a crash, that is, in theevent of an excessive load in the z-direction, this enables a directsupport of the bending region 26 on the first connecting leg 42, whichis directly opposite, either in alignment with the L-leg 41 or in closeproximity to the virtual center line 18 (FIG. 3) of the L-leg 41, inparticular on the side of the same which is outside of the rail. Theoverlap of the bending portion 26 with the first connecting leg 42 canpreferably correspond at minimum to the thickness of the lower rail, ifviewed in vertical projection from above. In conjunction with a smallgap size e (see FIG. 2) this enables a very effective support of theupper rail 2 on the lower rail 4 in the z-direction in the event of acrash. In the event of a crash, the region 29 without embossment servesas a predetermined bending position, which, as stated above, furtherenhances the diagonal bias of the two bearing areas 3, 5. In conjunctionwith the interlocking of the embracing portions in the second bearingarea 5, which increases with an increasing load, this results in a veryhigh stiffness of the rail profile.

A further increase in stiffness is caused by a cold work hardening ofthe material of the upper rail 2 in particular in the region of theembossings 10-15 in the event of a crash, when due to plasticdeformation in particular in these regions the dislocation density inthe metal microstructure is further increased.

In the following the dimensions of the gaps existing in a rail profilein accordance with the first embodiment will be described in more detailby way of example with reference to FIG. 2. Firstly the dimensions ofthe gaps in the z-direction will be described, which are relevant for afrontal or rear crash. From FIGS. 1 and 2 one can derive that a gap ofdimension a exists between the inside of the upper area of reversal 47and the front free end 28, that a gap of dimension b exists between thefront free end 48 and the outside of the inclined connecting leg 25,that a gap of dimension c exists between the front free end 52 and theupper side of the bearing leg 22 and that a gap of dimension d existsbetween the front end of the inclined bearing leg 23 and the bottom ofthe base leg 51. Furthermore, a gap of dimension e exists between theinside of the first connecting leg 42 and the bending portion 26.According to a preferred embodiment, the geometry of the rail profile isconfigured such that all gap dimensions a-d, preferably including thegap dimension e, are exactly the same, in line with the standardmanufacturing tolerances. This allows at least in the event of a crashwith intermediate tension, i.e. without a moment in the longitudinaldirection of the vehicle, an exactly simultaneous force absorption and amutual contact of directly opposite profile portions, so that a highstiffness can be accomplished, which is uniform over the entire railprofile. Also in the event of a crash with torque, i.e. of an off-centeracting tension, the aforesaid simultaneous force absorption and directsupport can be accomplished at least in section, if viewed in thelongitudinal direction of the rail profile.

In the vehicle transverse direction (y) the following gap dimensionsexist: a gap of dimension f exists between the inside of the circulararc-shaped bearing area 27 and the opposite free end 48, a gap ofdimension g exists between the free end 48 and the connecting leg 24, agap of dimension h exists between the L-leg 21 and the free end 52 and agap of dimension I exists between the free end 52 and the front end ofthe inclined supporting leg 23. According to a further embodiment, whichis optimized for a side crash situation, all the aforesaid gapdimensions in the y-direction are exactly the same, in line with thestandard manufacturing tolerances, so that also (or alternatively) inthe event of a side crash a simultaneous absorption of forces and asimultaneous contact between directly opposite portions of the railprofiles occurs.

Important to mention in this connection is the function of theembossings or embossments formed by cold working, which result in afurther increase of the rigidity of the rail profiles in z-direction inthe event of a crash.

In the following, other important aspects of the geometry and leverdimension of a rail profile according to the present invention, whichare related to the high rigidity of the rail profile according to theinvention, will be described with reference to FIGS. 2 and 3. It shouldbe emphasized that the aspects to be described in the following ingeneral may be combined and/or eliminated as desired. According to FIG.2 the rail profile has a total width B and a total height H. Theinternal width of the inner space I is B′. Because the first bearingarea 3 according to the invention is very close to the L-leg 41,according to the invention a ratio of B/B′=2.0 can be accomplished,while according to the prior art always B/B′>2.0 applied. In otherwords, the rail profile of the present invention can be formed verynarrow in the region of the base leg as compared to the prior art whilehaving a high rigidity and torsional strength, which can meet even highdemands concerning the installation space in today's motor vehicles. Itshould be emphasized that this outstanding ratio cannot be implementedaccording to the prior art.

As regards the geometry of the bearing areas 3, 5, if K is the maximumheight of the first bearing area 3, if L is the height or level of thecenter of the balls 7 in the first bearing area 3, if M is the maximumheight of the second bearing area 5 and if N is the center of the balls8 in the second bearing area 5, the following relationship may apply:M/N=K/L, in line with the manufacturing tolerances, wherein a maximum ofabout 4‰, more preferably a maximum of 2‰ can be specified for theaccuracy of the above ratios. The ratio M/N is in particular 1.33, whilethe ratio K/L is about 1.3.

If the height of the L-leg 41 up to the embossing or the transition areato the first connecting leg 42 is denoted by K′, then further thefollowing applies: (K−K′)/K′=K/L, namely in line with the standardmanufacturing tolerances in the range of one-tenth of a percent. Inparticular, this ratio can be 1.33.

Referring to FIG. 4, a second embodiment will be described, with theemphasis being placed in the description on the differences from thefirst embodiment. In contrast to the first embodiment, the base leg 40is not formed flat but stepped, wherein the base leg 40 is followed by asubstantially rectangularly bent connecting leg 53 still within theinterior space I of the rail profile, which is followed by supportingleg 54 extending in parallel with the base leg 40, which is spaced apartto and in parallel with the supporting leg 22 and serves for mounting(supporting) the rollers 9 in the second bearing area 5. The heightdifference a between the supporting leg 54 and the base leg 40 can befor example 7.0 mm, and allows a free space formed below the interiorspace I, which can be used for other purposes, for example for lockingof locking pins of a locking device of a longitudinal adjustment deviceof the longitudinal guide, which will be described in more detail belowwith reference to FIGS. 6 to 10. Alternatively, in the space thus formedalso cables and/or wires can be guided. In order to support the railprofile on the bottom of the vehicle interior, blocks or sections may beused which are screwed, welded, glued or otherwise fastened to thebottom plate. The free space thus formed also allows mounting andinstallation operations for such locking devices, cables and/or wires ina different order.

FIG. 5 a shows again the rail profile according to FIG. 1. In the eventof a crash, in this embodiment the inclined connecting legs 25 is fullysupported on the entire surface of the opposite first connecting leg 42,which allows an even more effective support in the z-direction in theevent of a crash.

In the fourth embodiment shown in FIG. 5 b at first according to theembodiment shown in FIG. 5 an inclined connecting leg 25 is provided,which extends obliquely downward. This may be the case, but is notnecessarily so. In principle the inclined connecting leg 25 can alsoextend obliquely upwards. A further difference is the shaping of thesecond bearing area, namely that the contact area or inclined supportingleg 50 is followed by connecting leg 55, which is basicallyperpendicular to the base leg 40, which is bent in the bending section56 by substantially 180°, and merges into the free end 52, whichprotrudes downwardly into the gap between the inclined supporting leg 23and L-leg 21 and is perpendicular to the base leg 40. Between thecontact area 50 and the opposite inclined connecting leg 23 further abearing or support of the rollers 8 is accomplished, wherein the rollers8 further have a lateral play in this bearing area 50, preferably aminor lateral play. This shaping of the embracing portion of the lowerrail 4 enables a further stiffening due to the additional bending of theend of the lower rail 4.

In this context in the following a further important characteristic ofthe rail profile of the present invention will be discussed withreference to FIG. 2, which may be combined with the aforementionedaspects of the invention. According to FIG. 2, the top surface of thebase leg 20 is not aligned with the upper area of reversal 47 in thefirst bearing area 3. Rather, the base leg 20 projects by a distance Gfrom the upper area of reversal 47. In the unloaded state of thelongitudinal guide 1 this distance G should be less than twice thethickness of the material of the upper rail, but should preferably lienear this upper limit. This allows a certain amount of “breathing” ofthe rail profile in the event of a vertical load, and in particular inthe operating position when a relatively heavy weight person takes seaton the vehicle seat. In this loaded normal state the rail profile“sags”, so that in particular the distance G decreases, namely up to theorder of less than about 0.5 mm in the case of particularly heavypeople, for example, with a body weight of 120 kg to 150 kg. Since thez-position of the balls 7 in the first bearing area 3 is substantiallyconstant due to the shaping is, this “breathing of the rails” leads to abending and pivoting of the inclined connecting leg 25 about thepredetermined bending position 29. According to the present invention,the geometry of the rail profile is such that, in this loaded normalstate, in particular if loaded by particularly heavy persons forexample, with a body weight of 120 kg to 150 kg, all gap dimensions inthe z-direction are exactly the same, in line with the manufacturingtolerances.

The longitudinal position of the rails relative to each other isdetermined by a conventional locking device as disclosed, for example,in documents DE 203 13 954 U1 and DE 101 27 153 A1 of the applicant oras described in European patent application EP 1316466 A1, the wholecontents of which is hereby explicitly incorporated by way of reference.Examples of such locking devices are to be described in more detailbelow with reference to FIGS. 6 to 10, for which a basic profileaccording to the first embodiment is respectively considered. However,it should be noted explicitly that the aspects to be described in thefollowing, which are related to the locking, in principle can also beindependent of such a rail profile and could also be claimed by claimsindependent from the particular shaping of such a rail profile.

According to FIG. 6, a guide web 71 is attached on the inside of theL-leg 21, for example by welding, the front free end of which is bent atan acute angle and passes into a supporting portion 72, the front faceof which extends in parallel with the inclined connecting leg 25 of theupper rail 2. In the normal state a gap is formed between the bearingportion 72 and the inclined connecting leg 25. In the event of a crash,a mutual contact of the regions 25, 72 and thus a further support in thez-direction and y-direction may occur. In the guide web 71 openings (notshown) are formed through which the locking pins 64 of a locking means(not shown in detail) extend. At the front free end of the locking pins64 frustoconical portions 65 are formed which engage locking openings inthe known way or interfere with them, which are formed in the base leg40 and are not shown here, in order to define the longitudinal positionof the upper rail 2 relative to the lower rail 4.

In contrast to the case of FIG. 6, according to FIG. 7 a locking web 73is fixed to the base leg 40 by means of the two lateral verticalconnecting webs 74, said locking web extending in longitudinal directionand being provided in the interior space of the rail profile. In such anembodiment the locking openings (not shown) are formed in the lockingweb 73, so that in the base leg 40 no locking openings need to be formedin the base leg 40, which would weaken the material thereof. In afurther embodiment additional locking openings can also be formed in thebase leg 40 in alignment with the locking openings in the locking web73, and possibly with a smaller diameter than these.

FIG. 8 shows further details of a locking device, such as this may alsobe employed in the embodiments according to FIGS. 6 and 7. According toFIG. 8 openings, which are not shown in detail, are formed in the baseleg 20, which are penetrated by the locking pins 64 of the lockingdevice. The upper end of the locking pins 64 is formed by a pin plate 66having a larger diameter. Above the guide web 71 a tapered portion 67 isformed on the locking pins 64, which serves as a receptacle forreceiving the front end of a compression spring 68 whose opposite end issupported on the inside of the base leg 20, so that the lock pins 64 areresiliently biased against the lower base leg 40. On the outer side ofthe upper base leg 20 a support plate 69 is fixed, in particular welded,on which the claws 70 of the locking device are supported. The lockingdevice is coupled to an easy-entry mechanism 60, which is fastened onthe side surface of the L-leg 21 of the upper rail 2 via the baseportion 61 and comprises a coupling member 63, which is coupled to thebackrest of a motor vehicle seat (not shown). As disclosed for examplein DE 101 27 153 A1 of the applicant, by means of the easy-entrymechanism a central unlocking of all locking pins can be accomplishedwhen the backrest is pivoted towards the seat surface of the seat frame,so that the entire motor vehicle seat can be moved forward in order toenable the boarding of a passenger into a rear area. This function isespecially useful for two-door cars or also in the rear area forvehicles with three or more rows. By actuating the easy entry mechanismor by manually operating the locking device, the locking pins 64 can beunlocked by lifting the claws 70 in order to allow a displacement of theseat in the longitudinal direction. According to FIG. 8 as a differenceto FIGS. 6 and 7 the guide web 71 is mounted at a very low position onthe L-leg 21 and the length of the supporting area 72, which extendsobliquely upwards and outwardly from the rail, is correspondinglyextended.

In contrast to FIG. 8, according to FIG. 9 a locking web 73 is attachedto the inside of the base leg 40 in a similar manner as in theembodiment according to FIG. 7, in which a plurality of locking openingsare formed, which are regularly spaced to each other, to receive thereinthe locking pins 64 and to thereby lock the longitudinal position of themotor vehicle seat. Although it is shown in FIG. 9, that thefrustoconical pins 65 also penetrate openings (not shown) in the baseleg 40 for locking, according to this embodiment the locking basicallycan also be accomplished only by means of the locking openings (notshown) in the locking web 73 so that no locking openings need to beformed in the base leg 40.

Deviating from all of the above embodiments, in the embodiment accordingto FIG. 10 the lower base leg 40 is interrupted in y-direction whileforming a free space 58 which is bridged by means of a connecting web57, which is attached, in particular welded, to the two ends of the baseleg 40. This free space 58 and the connecting web 57 may extend over theentire length of the lower rail 4, but may also be shorter than thelower rail, so that the base leg is not necessarily interrupted at thefront and/or rear end of the lower rail. The connecting web 57 may, inparticular consist of a harder material so as to receive the lockingpins in the non-illustrated locking openings more reliably. Theconnecting web 57 can be used as a complement, of course, to secure thelower rail 4 at the bottom of the vehicle interior.

Deviating from FIG. 10 according to FIG. 11, the lower base leg 40 isformed to overlap, that is with two mutually overlapping base legs 40 dand 40 f, which are in a full contact with each other and which arepreferably rigidly connected with each other, in particular by welding,also by means of a plurality of welding points. Here, the lower base legagain extends over substantially the entire width of the interior spaceI of the rail profile and thus has base legs 40 a, 40 b, which arealigned with each other and are followed by connecting legs 40 e, whichextend obliquely upwards and inwards to the rail, between which finallythe connecting leg 40 f is formed centrically, which is formedsymmetrical to the inner space of the rail profile formed by the baseleg 21 and the connecting leg 24 of the lower rail 4. In a correspondingmanner, the length of the L-leg 41 is reduced in this embodiment by thematerial thickness of the lower rail 4, so that the base leg 40 c isfollowed by the connecting leg 40 e, which extends obliquely upwards andinwards to the rail, which is followed by the base leg 40 d. In thisembodiment the base leg 40 b again also serves as a bearing area for therollers 9 in the second bearing area, as described above.

FIGS. 12 to 18 disclose further modifications in the region of the baseleg 40 of a lower rail 4 according to further embodiments which shallcooperate in a form-fitting manner or by positive fitting with a lockingdevice not described hereinafter in more detail.

For this purpose, according to FIG. 12 evenly spaced recesses 80 a, 80 bare formed in the base leg 40, if viewed in the longitudinal direction,from which locking teeth 81 a, 81 b protrude substantiallyperpendicularly, which shall cooperate in a form-fitting manner or byfriction with locking devices not specified herein in detail. Therecesses are divided into two alternating groups of recesses 80 a and 80b, which are alternately offset transversely to the longitudinaldirection of the rail. The recesses 80 a, 80 b can be formed byappropriate processing steps, such as punching or laser cutting, wherebythe locking teeth 81 a, 81 b are bent in a suitable manner. FIG. 13shows an enlarged sectional view of the embodiment according to FIG. 12.

In contrast to FIGS. 12 and 13 in the embodiment according to FIG. 14the recesses 80 are aligned with each other in the longitudinaldirection of the rail and are arranged at even intervals, namely in themiddle of the L-shaped region of the lower rail 4. Thus, the lockingteeth 81 are bent in the same directions, deviating from FIGS. 12 and 13respectively.

Deviating from FIG. 14, in the embodiment according to FIG. 15 thelocking teeth are oriented in the opposite direction.

Deviating from the previous embodiments, in the embodiment according toFIG. 16 locking lugs 82 are formed instead of locking teeth, which arerespectively connected to the base leg 40 of the lower rail 4 vialateral connecting webs 83 a, 83 b and which are formed integrallytherewith. Such locking lugs 82 may be formed by appropriately punchingor laser cutting of rectangular recesses and stamping or deforming ofthe so formed areas.

Deviating from the embodiments according to FIGS. 12 to 15, in theembodiment according to FIG. 17 the locking teeth 81 a, 81 b are notrespectively bent by 90° relative to the base leg 40 but instead at anacute angle which may be, for example 60°. As well as in the embodimentaccording to FIG. 13, the locking teeth 81 a, 81 b are oriented inopposite directions, wherein the recesses 80 a, 80 b are divided intotwo alternating groups of recesses 80 a and 80 b, that are alternatelyoffset transversely to the longitudinal direction of the rail, as in theexemplary embodiment according to FIGS. 12 and 13.

Finally, FIG. 18 shows a further embodiment, wherein the locking teeth81 a, 81 b are not rectangular but tapered, having a flattened lockingtip 84 which forms the end of two lateral inclined connecting sections85.

Although above in connection with the first connecting leg 42 it hasalways been disclosed that it extends obliquely upwards and seemedoutwardly of the rail from the L-leg 41 of the lower rail 4, in thisarea there is space for more advantageous modifications, which will beexplained in an exemplary manner with reference to the following FIGS.19 and 20, but can also correspondingly be applied to all of theaforesaid embodiments.

FIG. 19 shows a sectional view of an exemplary modification of thelongitudinal guide according to FIG. 1, wherein the first connecting leg42′ extends substantially horizontally between the L-leg 41 of the lowerrail 4 and the central connecting leg 43, preferably horizontally andoutwards from the rail. In the event of a crash, particularly in theevent of a frontal impact of the vehicle or a rear-end collision, therail strives forward relative to the body due to the inertia. However,since the movement of the slide rail is delimited due to locking, therear part of the slide rail is lifted towards the front region of thevehicle body and bent. Therefore a strong bending moment acts on theslide rail, in particular strongly vertically downwardly acting forces,so that the opposite bending area 26 would be pressed verticallydownward until it either gets in direct contact with the directlyopposite first connecting leg 42′ or initially gets in contact at thecentral connecting leg 43, slides downwards at this central connectingleg until it gets in contact at the opposite first connecting leg 42′.Due to the horizontal orientation of the first connecting leg 42′ afurther sliding of the opposite bending area 26 inwards to the rail iseffectively prevented and thus a “collapsing” of the rail profile 1 isprevented.

As will become easily apparent to the skilled person, the firstconnecting leg 42′ alternatively can extend downwards and outwards fromthe rail at a relatively small acute angle relative to a horizontal lineor relative to the base leg 40 of the lower rail 4. In particular thisangle may be in the range between 10° and 30°, more preferably between15° and 20°. In the event of a crash, especially at very strong forcesacting vertically downwards, and in the event of a contact of thebending area 26 at the opposite first connecting leg 42′, a furthersliding of the opposite bending area 26 inwards to the rail and thus a“collapsing” of the rail profile 1 can be effectively prevented due tothe direction in which the first connecting leg 42′ extends. At most,the bending area 26 would slip gradually further along the firstconnecting leg 42′ obliquely and outwardly, wherein the region a mutualcontact would, however, be in any case relatively close to or on avirtual center line 18 (see FIG. 3) and thus a further bending of thefirst connecting leg 42′ would occur only if extremely high forces wouldprevail.

According to the invention this modification in the area of the firstconnecting leg 42′ may be carried out for all embodiments set forthabove, as illustrated by way of example with reference to FIG. 20, whichshows a sectional view of another exemplary modification of theembodiment according to FIG. 19 with an exemplary locking device andeasy-entry-mechanism, as described above with reference to FIG. 8. For agood support, the gap between the first connecting leg 42′ and theopposite bending area 26 should be small. This support can be furtherenhanced by the cooperation of the inclined connecting leg 25 with adirectly opposite support portion of a guiding or locking web 71 (seeFIG. 6), as described above by way of example with reference to FIG. 6.

Embodiment 1

In an exemplary embodiment of a rail profile according to the firstembodiment, the following exemplary geometry and dimension may apply:the thickness of the upper rail is 1.5 mm, whereas the thickness of thelower rail is 1.7 mm (manufacturing tolerance each 0.08 mm). The depthof the embossments, as indicated in area 12 by the arrow in FIG. 2, is0.2 mm. In the region of the embossments 10 to 15 the radius ofcurvature or the bending radius of the respective rail portion issmaller than without embossments. The total width B is 47.0 mm, theclear inner width of the interior space I is 23.5 mm. The clear innerwidth C of the upper region of the interior space is 18.4 mm, thedistance of the ball centers D is 38.5 mm. The dimensions of the gaps iny-direction are preferably all identical and are 1.0±0.02 mm.

The maximum height K of the first bearing area in the unloaded state is32.5 mm, the level of the balls 7, as measured from the underside of thebase leg 40, is 25 mm, the length of the L-leg 41 is 15 mm, the maximumheight of the second bearing area is equal to 16.8 mm, the level of theupper rollers in the second bearing area, as measured from the undersideof the base leg 40, is 12.5 mm. The maximum height H of the rail profileis 35 mm. The dimensions of all gaps in the z-direction, in particularof gaps a to c, and preferably of gapes a to d, are all the same andamount to 1.02±0.02 mm. The gap width e is 1.05 mm, but can be selectedthe same as the gap dimensions in the z-direction.

The radius of the balls 7 is 5.0 mm, the bending radius of the circulararc-shaped bearing area 44 is 4.8 mm, which also applies to the radiusof curvature of the circular arc-shaped bearing area 27 and the radiusof curvature of the corner area 44 in the first bearing area. The radiusof curvature of the bending area 26 is 2.2 mm, the embossment 10 in thebending area 26 is engaged by about 0.2 mm, so that there the radius ofcurvature is 1.8 mm.

The length O of the free end 48 is 7.8 mm, the length of the free end 52is 5.1 mm, as viewed in each case until the underside of the associatedbase leg 47 and 51, respectively. The acute angle included by theinclined supporting leg 23 and the base leg 22 is 55°. The diameter ofthe upper rollers 8 in the second bearing area is 3.0 mm.

The radius of the lower rollers 9 in the second bearing area is 5.0 or6.0 mm.

Other Embodiments

In the following improvements of a rail profile according to the presentinvention will be discussed in an exemplary manner, taking as referencea rail profile according to the German utility model DE 20 2004 010 49U1 that has a specific line weight (weight per unit length oflongitudinal guide in the longitudinal direction) of 2.6 g/mm for agiven a material thickness of the upper and lower rail of 1.7 mm, anoverall width B (see FIG. 2) of 48 mm and a total height H of 35 mm. Forthe reference profile and the profiles to be discussed hereinparticularly the total line weight (in units of g/mm per unit length ofthe rail profile) and the area moment of inertia in the z-direction (inunits of mm⁻⁴) will be compared.

In a first embodiment corresponding to the profile according to FIG. 1,the material thickness of the lower rail was kept constant (1.7 mm),however, the material thickness of the upper rail was reduced to 1.5 mm.The total width was reduced to 47 mm, but the width at the lower end ofthe rail profile could be significantly reduced and the total heightcould be increased by 7% to 37.5 mm. The total line weight wasessentially the same (deviation: 1%), but the area moment of inertia ofthe lower rail could be increased by 31% and the area moment of inertiaof the upper rail by 17%.

In a second embodiment corresponding to the profile according to FIG. 1,the material thickness of the lower rail 1 was increased to 8 mm and thematerial thickness of the upper rail was reduced to 1.5 mm. The totalwidth was reduced to 47.2 mm, but the width at the lower end of the railprofile could be significantly reduced and the total height could beincreased by 7% to 37.6 mm. Total weight of the line was about 10%larger. Herein, the area moment of inertia of the lower rail could beincreased by 48% and the area moment of inertia of the upper rail couldbe increased by 17%.

In a third embodiment corresponding to the profile according to FIG. 5b, the material thickness of the lower rail was increased to 1.8 mm andthe material thickness of the upper rail is was increased to 1.5 mm. Thetotal width was reduced to 47.2 mm, but the width at the lower end ofthe rail profile could be reduced significantly and the total heightcould be increased by 7% to 37.6 mm. The total line weight was about 12%larger. Herein, the area moment of inertia of the lower rail could beincreased by 49% and the area moment of inertia of the upper rail couldbe increased by 20%.

Due to the aforementioned geometry, the “difference in height” betweenthe balls 7 and the upper rollers 8 in the second bearing area 5 can beincreased further in the vertical direction as compared to the priorart, to thereby increase the aforementioned diagonal biasing of thebearing areas 3, 5 relative to each other.

It is expressly pointed out that the manner of forming the base leg ofthe lower rail and of the locking of the rail profile as described abovewith reference to FIGS. 6 to 11 and FIGS. 12 to 18 can in principle beconsidered independently from the rail profile according to the presentinvention described with reference to the FIGS. 1 to 5 b, and can alsobe used in rail profiles with any other geometries, in particular in arail profile in accordance with WO 2006/10 60 44 A2 or DE 101 27 153 A1of the applicant. As regards further details of the locking device andof the easy-entry mechanism reference is made especially to DE 101 27153 A of the applicant, the entire content of which is hereby expresslyincorporated in the present application by way of reference.

Although above various aspects of the invention have been described interms of specific embodiments it is expressly pointed out that thevarious aspects of the invention can also be considered and claimedindependently, especially as concerns the rail profile, the actualgeometric location of the two bearing areas, the specific configurationof the two bearing areas, the further stiffening of the rail profiles bymeans of embossings or embossments, the selected dimensions of the gapsand the geometry and details of the configuration of the base leg of thelower rail and the locking device. These aspects of the invention areintended expressly to be separately subject thereof of patentapplications claiming priority, divisional applications or patentapplications directed to further developments.

LIST OF REFERENCE NUMBERS

-   1 Rail/longitudinal guide-   2 Upper rail-   3 First bearing area-   4 Lower rail-   5 Second bearing area-   6 Ball-   7 Ball-   8 Roll-   9 Roll-   10 Embossment-   11 Embossment-   12 Embossment-   13 Embossment-   14 Embossment-   15 Embossment-   17 virtual extension line-   18 Center line-   19 Contact point of the balls 7 in the first bearing area-   20 Base leg of the upper rail-   21 L-leg-   22 Supporting leg-   23 Free end/oblique supporting leg-   24 Connecting leg-   25 Oblique connecting leg-   26 Bending region-   27 Embracing area/bearing area-   28 Free end-   29 Predetermined bending position-   40 Base leg of the lower rail-   40 a base leg-   40 b base leg-   40 c base leg-   40 d base leg-   40 e Oblique connecting leg-   40 f connecting leg-   41 L-leg-   42 Oblique connecting leg-   42′ Connecting leg-   43 central connecting leg-   44 embracing area/bearing area-   45 upper connecting leg-   47 Top area of reversal-   48 Free end-   50 Supporting portion-   51 Base leg in the embracing portion-   52 Free end-   53 Connecting leg-   54 Supporting leg-   55 Connecting leg-   56 Bending region-   57 Connecting web-   58 Clearance-   60 Easy-entry mechanism-   61 Base portion-   62 Rotation axis-   63 Coupling member-   64 Locking pin-   65 Taper pin-   66 Pin plate-   67 Tapered section/receptacle for spring-   68 compression spring-   69 support plate-   70 claw-   71 guide web-   72 support portion-   73 Locking web-   74 connecting web-   80 recess-   80 a recess (first group)-   80 b recess (second group)-   81 locking tooth-   81 a locking tooth (first group)-   81 b locking tooth (second group)-   82 locking lug-   83 a left connecting web-   83 b right connecting web-   84 tip-   85 inclined surface

1. A longitudinal guide for vehicle seats, in particular motor vehicleseats, comprising two elongate rails, each of said rails comprising alower rail, an upper rail supported thereon so as to be movable in alongitudinal direction, and two bearing areas for guiding means, whichare disposed diagonally opposite to each other and are biased againsteach other, each upper and lower rail having an L-shaped region, ifviewed in profile, which is formed by a base leg and an L-leg projectingfrom the base leg essentially perpendicularly, and two end portionswhich are respectively connected to the L-shaped region, wherein eachend portion of the upper or lower rail together with the end portion ofthe associated lower or upper rail form an embracing area under mutualinterlocking, the end portions of the upper rail together with oppositeportions of the associated lower rail form the bearing areas, and asingle group consisting of a plurality of balls is supported in a firstbearing area at the end portion which is formed as a circular arc-shapedprofile, wherein the first bearing area is formed by a corner area ofthe lower rail and by the end portion of the upper rail formed as acircular arc-shaped profile a first connecting leg of the L-leg of theL-shaped region of the lower rail projects outwardly below a bentportion of the upper rail and the corner area is formed on a secondadjoining connecting leg connected with the first connecting leg.
 2. Thelongitudinal guide as claimed in claim 1, wherein the first connectingleg (42) projects obliquely upwardly from the L-leg (41) of the L-shapedregion of the lower rail (4) and outwards from the rail.
 3. Thelongitudinal guide as claimed in claim 1, wherein the first connectingleg (42′) of the L-shaped region of the lower rail (4) projectsobliquely downwardly from the L-leg (41) of the L-shaped region of thelower rail (4) and outwards from the rail.
 4. The longitudinal guide asclaimed in claim 1, wherein the first connecting leg (42′) of the L-leg(41) of the L-shaped region of the lower rail (4) projects horizontallyand outwards from the rail.
 5. The longitudinal guide as claimed inclaim 1, wherein in a transition area between a connecting leg (24)opposite to the L-leg of the upper rail (2) and the adjoining endportion (28) a predetermined bending position (29) is provided which isless stiff than curved or bent portions (10, 11) of the upper rail (2)adjacent thereto.
 6. The longitudinal guide as claimed in claim 5,wherein at least one adjacent curved or bent portion of the upper rail(2) is provided with an embossment (10, 11) formed by cold work formingto effect a higher stiffness, said embossment(s) being preferably formedwith an even curvature.
 7. The longitudinal guide as claimed in claim 6,wherein the adjacent curved portions, which are each provided with theembossment (10, 11), are a corner area of the L-shaped region of theupper rail (2) and a transition area between a slanted connecting leg(25), which adjoins the connecting leg (24) opposite to the L-leg (21)of the upper rail (2), and the circular arc-shaped end portion (28) ofthe upper rail (2).
 8. The longitudinal guide as claimed in claim 6,wherein the inclined connecting leg (25) extends obliquely downwards andoutwards from the rail, and wherein the transition area between theobliquely downwardly and outwardly extending connecting leg (25) and theend portion (28) of the upper rail (2) formed as a circular arc-shapedprofile is formed as a bending portion (26).
 9. The longitudinal guideas claimed in claim 8, wherein the bending portion (26) liessubstantially on a virtual center line (18) through the L-leg (41) ofthe L-shaped region of the lower rail (4) projecting substantiallyperpendicularly from the base leg (40) or lies on an opposite side of avirtual center line (18) through the L-leg (41) of the L-shaped regionof the lower rail (4), if viewed from an inner space (1) of the rail.10. The longitudinal guide as claimed in claim 8, wherein the upper rail(2) is bent by about 180 degrees at the bending portion, andsubstantially reverses the direction of extension.
 11. The longitudinalguide as claimed in claim 7, wherein the inclined connecting leg (25)extends obliquely upwards and outwards from the rail and wherein thetransition area between the obliquely downwardly and outwardly extendingconnecting leg (25) and the end portion (28) of the upper rail (2),which is formed as a circular arcuate profile, is formed as a bendingportion (26), which lies substantially on a virtual center line (18)through the L-leg (41) of the L-shaped region of the lower rail (4)projecting substantially vertically from the base leg (40).
 12. Thelongitudinal guide as claimed in claim 8, wherein the bending portion(26) is spaced apart and opposite to the center of the first connectingleg (42; 42′) for support in the event of a crash.
 13. The longitudinalguide as claimed in claim 1, wherein the corner area (44) is formed bythe second connecting leg (43) and an upper connecting leg (45) angledfrom the second connecting leg.
 14. The longitudinal guide as claimed inclaim 13, wherein the second connecting leg (43) and the upperconnecting leg (45) enclose an angle in the range from 100 degrees to120 degrees, more preferably an angle in the range from 112.5 degrees to107.5 degrees, and more preferably an angle of about 110 degrees, andwherein a rounded inner corner is formed on an inner side of the cornerarea (44) the radius of curvature of which is matched to the radius ofcurvature of the balls (7) mounted in the first bearing area (3). 15.The longitudinal guide as claimed in claim 1, wherein contact points(19) of the balls (7) at the end portion (28) formed as a circulararc-shaped profile are on an opposite side of a virtual center line (18)through the L-leg (41) of the L-shaped region of the lower rail (4), ifviewed from an interior space (I) of the rails.
 16. The longitudinalguide as claimed in claim 15, wherein the distance between the contactpoints (19) to the virtual center line (18) is less than a materialthickness (SOS) of the upper rail (2) or corresponds to this materialthickness (SOS).
 17. The longitudinal guide as claimed in claim 15,wherein the contact points (19) further lie on a virtual extension lineof the outer side of the L-leg (41) of the L-shaped region of the lowerrail (4) or lie outside of this virtual extension line, if viewed froman interior space (I) of the rails.
 18. The longitudinal guide asclaimed in claim 17, wherein the distance of the contact points (19) tothe virtual extension line (17) is considerably less than a materialthickness (SOS, SBS) of the upper or lower rail (2, 4).
 19. Thelongitudinal guide as claimed in claim 1, wherein all clearances (a-d)in the embracing areas of the bearing areas (3, 5) in a directionperpendicular to the base leg (40) of the L-shaped region of the lowerrail (4) are the same and are less than a material thickness (SOS) ofthe upper rail (2).
 20. The longitudinal guide as claimed in claim 1,wherein all clearances (f-i) in the embracing areas of the bearing areas(3, 5) parallel to the base leg (40) of the L-shaped region of the lowerrail (4) are the same and are less than a material thickness (SOS) ofthe upper rail (2).
 21. The longitudinal guide as claimed in claim 1,wherein a top surface of the base leg (20) of the L-shaped region of theupper rail (2) protrudes from an upper reversal area (47) of the lowerrail (4) in the embracing area of the first bearing area (3) by apredetermined distance (G), which is less than twice the materialthickness of the upper rail (2) in an unloaded state of the longitudinalguide (1).
 22. The longitudinal guide as claimed in claim 1, wherein aplurality of first rollers (9), which are supported preferably with alateral play between the base leg (40) of the L-shaped region of thelower rail and an opposite supporting leg (22) of the upper rail (2)extending in parallel thereto, and a plurality of second rollers (8) aresupported in the second, diagonally opposite bearing area (5), which aresupported preferably with a lateral play between the end portion of theupper rail (2) formed as a supporting leg (23) extending at an acuteangle obliquely upwardly and an opposite inclined supporting leg (50)extending in parallel between a first connecting leg (49) adjoining thebase leg (40) and extending vertically upwardly and a horizontal baseleg (51) of the embracing area in the end region of the lower rail (4)connected therewith.
 23. The longitudinal guide as claimed in claim 22,wherein the base leg (51) of the embracing area in the second bearingarea (5) is connected with a connecting leg (55), which is substantiallyperpendicular to the base leg (40) of the L-shaped region of the lowerrail (4), a bending portion (56) and a free end (52) of the lower rail,which is substantially perpendicular to the base leg (40) of theL-shaped region (4) and is projecting downwardly.
 24. The longitudinalguide as claimed in claim 1, wherein said base leg (40) of the lowerrail (4) merges into a connecting leg (53) bent at a right angle belowthe base leg (20) of the upper rail (2), which passes over into asupporting leg (54) extending in parallel with the base leg (40) andserves for bearing the rollers (9) in the second bearing area (5),whereby a free space is formed below the base leg (40) of the lowerrail.
 25. The longitudinal guide as claimed in claim 1, wherein a guideweb (71) is provided on the inner side of the L-leg (21) of the upperrail (2), the front free end of which is bent at an acute angle andpasses into a supporting portion (72), the front end face of whichextends in parallel with and, in a normal state, at a small distance tothe inclined connecting leg (25) of the upper rail (2), which isfollowed by the bending region (26).
 26. The longitudinal guide asclaimed in claim 25, wherein openings are formed in the guide web (71)through which locking pins (64) of a latching and locking device extend,wherein front free ends of the locking pins (64) are engaged withlocking openings to define the longitudinal position of the upper rail(2) with respect to the lower rail (4).
 27. The longitudinal guide asclaimed in claim 26, wherein the locking openings are formed in the baseleg (40) of the lower rail (4) or in a locking web (73), which extendsin the longitudinal direction and is disposed in the interior space ofthe rail profile, which is fixed to the base leg (40) of the lower railby means vertical connecting webs (74) laterally disposed.
 28. Thelongitudinal guide as claimed in claim 1, wherein said base leg (40) ofthe lower rail (4) is interrupted in the transverse direction (y) tothereby form a free space (58), wherein the free space (58) bridged by aconnecting web (57) at least in a central portion of the rails, whichconnecting web is fixed at the two ends of the base leg (40).
 29. Thelongitudinal guide as claimed in claim 28, wherein the connecting web(57) is formed of a harder material than the base leg (40) of the lowerrail (4).
 30. The longitudinal guide as claimed in claim 1, wherein thelower base leg (40) is overlapping with two mutually overlappingstationary base legs (40 d, 40 f), which are in full contact with eachother, wherein the base member (40 d, 40 f) are fixedly connected toeach other.